Genetic characterization of Group B Streptococcus colonizing and invasive disease isolates in South Africa

Principal investigator: Shabir Madhi
Institution: University of the Witwatersrand, Johannesburg, South Africa
Co-investigators: Gaurav Kwatra, Odile Harrison, Martin Maiden, Arshad Ismail, Rob Hedyerman, Andrea Gori

Start date: July 2018

Group B streptococcus is a leading cause of neonatal invasive disease. This is traditionally further categorised as early onset disease (EOD; occurring at <7 days of age) which most commonly presents as sepsis, and late onset disease (LOD occurring between 7-89 days) that presents as sepsis or meningitis (40-50%). Furthermore, GBS has been associated with stillbirth. There is limited information on the genotypes of GBS causing maternal colonization and invasive disease among infants or associated with stillbirths in Africa, including South Africa. Investigating the genetic diversity of GBS could inform vaccine development, and would also be important to continue to monitor post-vaccine introduction to determine whether vaccination induces immunological pressure which might result in genetic changes aimed at evading vaccine induced immunity. This study will characterize GBS genotypes among infants with invasive disease, as well as GBS isolates associated with stillbirths and isolates associated with colonization among peripartum women of healthy babies from the same population.

Aim and Impact

Characterize GBS genotypes using whole genome sequencing to determine variations in virulence genes and other putative genetic elements that may contribute to invasive disease.